Document FR 2,791,929 proposed a presence detection device for a railway vehicle. The railway vehicle comprises at least one collector shoe that is placed in contact with a power supply segment arranged on the ground. Each segment comprises an antenna adapted to receive a presence signal sent by the railway vehicle. Each segment is adapted to send a return signal in response. When the railway vehicle does not receive a return signal, a switch placed between the collector shoe and the motor of the vehicle interrupts the electrical contact between the collector shoe and the motor immediately. This creates an abrupt deceleration of the railway vehicle.